Freeze plug size for 75 350!

[Karnawgie]

Trying to find some freeze plugs for my 75 YA 350.

I pulled the engine due to one popped freeze plug and am deciding to change a hand ful of them. The 3 on each side of the block, the two in the upper back of the block, and the two individual ones in the back of the head.

Rock auto labels them as a size close to 1 5/8", and I don't think I even saw one close to the head plug size.

I went to orileys, and there inventory has similar numbers. The problem is my block freeze plug is nearly 2", around 1.94". While I was there I ordered a plug that was 1.98 inches and I'm gonna pick it up and try it today.

As far as my head plug, it measures 1.36-1.38" and any plug close to that size, or 1 3/8" is a wierd special order. Why is it so hard to find some plugs!?

1975 grand lemans, original 350/350.

 

[melsg5]

https://www.napaonline.com/en/p/NOE567001

 

[Karnawgie]

https://www.napaonline.com/en/p/NOE567001

I see it says maximum diameter for those big plugs is 2.11, I had also compared my plug to a 2.1 and it definetly wouldn't have fit. These cheap plugs are flat and not tapered at all aswell, which wouldn't help. I've just got my dorman 555-105 from oriley and I'm gonna see how it fits soon.

 

[Karnawgie]

The 1.98 plug I've picked up seems like it'll compress just a little to fit, no way a 2.1 would fit. Now I've got to move onto to finding a couple 1 3/8" plugs.

______________________________

 

[melsg5]

this company only does Pontiacs

https://butlerperformance.com/c-1234734-gaskets-and-freeze-plugs-freeze-plugs-block-acc.html?srsltid=AfmBOoqaAq1WSeG1NRr3bFOEOXpGcyjf88QGwP0whbgUPkwxB7fXbow2

 

[Karnawgie]

Wanted to give an update to what plugs I used.

For the small ones in the head they're a 1 3/8", used a dorman 555-093.1, minimum diameter 1.37 max 1.396

The bigger block ones are just under 2", dorman 555-105 diameter 1.969.

I don't know why the auto parts stores struggle to find these but this is what worked for me, cheap fix to get it back on the road.